Audio Kit is an amazing new open source library that takes working with audio on iOS devices a step further providing for easy audio synthesis, processing and analysis.

Audio Kit includes many different audio synthesizers, and effects, a built-in sampler for recording audio stream, an audio sequencer and includes many different examples showing how to do neat things such as generating audio, pitch shifting, and creating a harmonizer.

Here are a couple of videos of some apps created with audio kit showing off some of the things you can do with Audio Kit audio generation, recording, and pitch shifting: